The new coronavirus is believed to be spreading throughout Yemen where the health care system “has in effect collapsed”, the United Nations said on Friday, appealing for urgent funding.

“Aid agencies in Yemen are operating on the basis that community transmission is taking place across the country,” Jens Laerke, spokesman for the U.N. Office for the Coordination of Humanitarian Affairs (OCHA), told a Geneva briefing.

“We hear from many of them that Yemen is really on the brink right now. The situation is extremely alarming, they are talking about that the health system has in effect collapsed,” he said.

Aid workers report having to turn people away because they do not have enough medical oxygen or sufficient supplies of personal protective equipment, Laerke said.

A flight carrying international aid workers landed in Aden on Thursday as air space opened up for rotations, but Yemeni nationals have been doing most of the on-site work, he said.

The main coronavirus treatment centre in southern Yemen has recorded at least 68 deaths in just over two weeks, Medecins Sans Frontieres (Doctors Without Borders), the medical charity running the site, said on Thursday.

The figure – more than double the toll announced by Yemeni authorities so far – suggested “a wider catastrophe unfolding in the city”, MSF said.

Yemeni authorities have reported 184 coronavirus infections including 30 deaths to the World Health Organization (WHO), the latest WHO figures showed overnight. “The actual incidence is almost certainly much higher,” Laerke said.

The United Nations estimates that it will seek $2 billion for Yemen to maintain aid programs through year-end, he added.

Yemen has been since March 2015 under brutal aggression by Saudi-led Coalition, in a bid to restore control to fugitive president Abd Rabbu Mansour Hadi who is Riyadh’s ally.

Hundreds of thousands of Yemenis have been killed or injured in the strikes launched by the coalition, with the vast majority of them are civilians.

The coalition, which includes in addition to Saudi Arabia and UAE: Bahrain, Egypt, Morocco, Jordan, Sudan and Kuwait, has been also imposing a harsh blockade against Yemenis.